1. Field of the Invention
The present invention relates to a molded fertilizer which improves plant growth by actively facilitating plant roots so as to spread over the molded fertilizer or to wrap the molded fertilizer.
2. Discussion of Background
Heretofore, in the field of gardening, tree planting or afforestation, there have been widely used fertilizers molded by a tablet-making molding machine or a briquetting machine in view of their persistent fertilizer effect or convenience in easy handling. For example, there have been known a molded fertilizer prepared by compression-molding isobutylidene diurea with a roll press, which is one of reaction products of urea and aldehydes (JP-B-54-24942) and a molded fertilizer prepared by tablet-making (U.S. Pat. No. 5,549,730). When these molded fertilizers having a persistent fertilizer effect are applied on plants, nutrient elements present in the vicinity of the surfaces of the molded fertilizers are gradually reduced at the latter stage of growth, and there is a phenomenon that the plants grow by making their roots wrap the molded fertilizers since fertilizer nutrient elements are present in the center part of the molded fertilizers.
An object of the present invention is to provide a molded fertilizer for gardening, tree planting or afforestation, which improves the growth of a plant by actively facilitating its roots to spread over or to wrap the molded fertilizer.
In order to achieve this object, the present inventors have intensively studied and discovered that an unexpectedly marvelous effect can be achieved by providing a secant line on the surface of a molded fertilizer, and the present invention has been accomplished on the basis of this discovery.